#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>

int appear_count(int arr[], int n,int len)
{
	int j = 0;
	int count = 0;
	for (j = 0; j < len; j++)
	{
		if (arr[j] == n)
			count++;
	}
	return count;
}

int main()
{
	int arr[9] = { 0 };
	int i = 0;
	for (i = 0; i < 9; i++)
	{
		scanf("%d", &arr[i]);
	}
	int sz = sizeof(arr) / sizeof(arr[0]);
	for (i = 0; i < 9; i++)
	{
		int ret = appear_count(arr,arr[i],sz);
		if (ret == 1)
			printf("%d\n", arr[i]);
	}
	return 0;
}